The invention relates to a process of manufacturing shaped bodies having cavities provided at both ends of the finished body as well as different outside diameters at both body ends. Such shaped bodies may be, for example, socket wrenches with different wrench widths at their two ends.
As a rule, such shaped bodies are manufactured by cold shaping from cylindrical metal pieces, designated hereinafter both in the initial form and in the intermediate forms to the finished product as stamped part, for short. This stamped part is shaped in several stamping stages, with different stamping tools which comprise in particular bottom dies and press rams.
It is known to carry out in each stamping stage only one stamping operation. It is further known to combine in one stamping stage also two shaping operations insofar as it involves the use of forward and backward extrusion cupping. In forward extrusion cupping the stamped part is pressed from behind over a stationary cupping ram, so that the material of the stamped part flows over the stationary cupping ram in the direction of the pressure exerted from behind.
In backward extrusion cupping, instead, the material of the stamped part flows counter to the direction of the exerted pressure over a movable cupping ram exerting the pressure.